Astrophysicists crack the case of 'disappearing' Sulphur in planetary nebulae

Two astrophysicists from the Laboratory for Space Research (LSR) at The University of Hong Kong (HKU) have finally solved a 20-year-old astrophysical puzzle concerning the lower-than-expected amounts of the element Sulphur found in Planetary Nebulae (PNe) in comparison to expectations and measurements of other elements and other types of astrophysical objects.

The expected levels of Sulphur have long appeared to be "missing in action." However, they have now finally reported for duty after hiding in plain sight, as a result of leveraging highly accurate and reliable data.

The team has recently reported their findings in Astrophysical Journal Letters.

Background

PNe are the short-lived glowing, ejected, gaseous shrouds of dying stars that have long fascinated and enthused professional and amateur astronomers alike with their colourful and varied shapes.

PNe live for only a few tens of thousands of years compared to their host stars, which can take billions of years before they pass through the PN phase on the way to becoming "white dwarfs." Consequently, PNe provide an almost instantaneous snapshot of stellar death throes.

They are a vital, scientific window into late-stage stellar evolution as their rich emission line spectra enable detailed studies of their chemical compositions.

The Enigmatic Sulphur Anomaly

Past studies showed that PNe optical spectra appeared to have a varying deficit of the element Sulphur.

This deficit was difficult to explain because Sulphur, known as an "α element," should be produced in lockstep with other elements like oxygen, neon, argon and chlorine in more massive stars.

As a result, its cosmic abundance should also be directly proportional.

Surprisingly, while strong correlations between Sulphur and Oxygen abundances have been observed in H II regions (Hydrogen ionised region) and blue compact galaxies, PNe originating from low- to intermediate-mass stars consistently exhibit lower Sulfur levels, giving rise to the so-called mysterious "sulfur anomaly" that has perplexed and annoyed astronomers for decades.

Our Work Solving the Mystery

Ms Shuyu TAN, a graduate of HKU MPhil in Physics and Research Assistant at HKU LSR, along with her supervisor Professor Quentin PARKER, the Director of LSR, utilised an unprecedented sample of exceptional high signal to noise (S/N) optical spectra for approximately 130 PNe located in the centre of our Galaxy.

This exceptional dataset had minimal background noise, allowing for a clear and detailed examination of the spectral features, helping the team effectively tackle and solve the mystery.

These PNe were observed using the world-leading European Southern Observatory (ESO) 8m Very Large Telescope in Chile.

It turns out the anomaly was essentially a result of poor data quality for Sulphur emission lines in PNe spectra.

It was found that using Oxygen as the base metallicity comparator to other elements was not accurate, and instead, Argon demonstrated a stronger correlation with Oxygen for Sulphur and has been suggested as a more reliable indicator of metallicity and a suitable comparison element.

So, when a large, carefully selected sample of PNe are spectroscopically observed at high S/N on a large telescope, not only did the data reveal a strong "lock-step" behaviour or Sulphur in PNe for the first time, as seen and expected for other types of astrophysical objects, but the anomaly itself effectively went away.

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Scientists develop artificial 'worm gut' to break down plastics

A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) has developed an artificial 'worm gut' to break down plastics, offering hope for a nature-inspired method to tackle the global plastic pollution problem.

By feeding worms with plastics and cultivating microbes found in their guts, researchers from NTU's School of Civil and Environmental Engineering (CEE) and Singapore Centre for Environmental Life Sciences Engineering (SCELSE) have demonstrated a new method to accelerate plastic biodegradation.

Previous studies have shown that Zophobas atratus worms -- the larvae of the darkling beetle commonly sold as pet food and known as 'superworms' for their nutritional value -- can survive on a diet of plastic because its gut contains bacteria capable of breaking down common types of plastic.

However, their use in plastics processing has been impractical due to the slow rate of feeding and worm maintenance.

NTU scientists have now demonstrated a way to overcome these challenges by isolating the worm's gut bacteria and using them to do the job without the need for large scale worm breeding.

NTU Associate Professor Cao Bin at the School of CEE and Principal Investigator at SCELSE said, "A single worm can only consume about a couple of milligrams of plastic in its lifetime, so imagine the number of worms that would be needed if we were to rely on them to process our plastic waste. Our method eliminates this need by removing the worm from the equation. We focus on boosting the useful microbes in the worm gut and building an artificial 'worm gut' that can efficiently break down plastics."

The study, published in Environment International in January, is aligned with the University's commitment to fostering innovation and translating research into practical solutions that benefit society under its NTU2025 five-year strategic plan.

Developing an artificial worm gut

To develop their method, the NTU scientists fed three groups of superworms different plastic diets -- High-density polyethylene (HDPE), Polypropylene (PP) and Polystyrene (PS) -- over 30 days.

The control group was fed a diet of oatmeal.

The NTU scientists selected the plastics as they are among the most common plastics in the world, used in everyday items like food boxes and detergent bottles.

HDPE is a type of plastic known for its high-impact resistance, making it difficult to break down.

After feeding the worms plastic, scientists extracted the microbiomes from their gut and incubated them in flasks containing synthetic nutrients and different types of plastics, forming an artificial 'worm gut'. Over six weeks, the microbiomes were left to grow in the flasks at room temperature.

Increase in plastic-degrading bacteria

The scientists found that compared to the control group, the flasks which contained the gut microbiomes from the plastic-fed worms showed a significant increase in plastic-degrading bacteria.

Furthermore, the microbial communities colonising the plastics in the flasks were simpler and more tailored to the specific type of plastic than the microbes found on plastics that had been fed directly to the worms . When the microbial communities are simpler and targeted to a specific type of plastic, this translates to potential for more efficient plastic degradation when used in real-life applications.

First author of the study Dr Liu Yinan, Research Fellow at the School of CEE and SCELSE, said, "Our study represents the first reported successful attempt to develop plastic-associated bacterial communities from gut microbiomes of plastic-fed worms. Through exposing the gut microbiomes to specific conditions, we were able to boost the abundance of plastic-degrading bacteria present in our artificial 'worm gut,' suggesting that our method is stable and replicable at scale."

The researchers say their proof-of-concept lays the foundation for developing biotechnological approaches that use worms' gut microbiomes to process plastic waste.

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Surprising behavior in one of the least studied mammals in the world

Some animals live in such remote and inaccessible regions of the globe that it is nearly impossible to study them in their natural habitats. Beaked whales, of which 24 species have been found so far, are among them: They live far from land and in deep oceanic waters, where they search for food at depths of 500 meters and more.

The record holder for the deepest dive by a mammal is a Cuvier's beaked whale, which in 2014 was measured to dive at least 2992 meters. A beaked whale also holds the mammalian record for the longest dive; 222 minutes.

Now, the world gets a new and surprising insight into the world of distant beaked whales through a scientific study of a population of Baird's beaked whales. The population has unexpectedly been found near the coast and in shallower waters than previously observed.

The study is led by whale biologists Olga Filatova and Ivan Fedutin from the University of Southern Denmark/Fjord&Bælt, and it is published in the journal Animal Behaviour.

Filatova and Fedutin have many years of whale studies in the northern Pacific behind them, and it was during an expedition to the Commander Islands in 2008 that they first saw a group of Baird's beaked whales near the coast.

"We were there to look for killer whales and humpback whales, so we just noted that we had seen a group of Baird's beaked whales and didn't do much about it. But we also saw them in the following years, and after five years, we suspected that it was a stable community frequently visiting the same area. We saw them every year until 2020, when Covid 19 prevented us from going back to the Commander Islands," explains Olga Filatova, a whale expert and postdoc at Department of Biology and SDU Climate Cluster, University of Southern Denmark.

The studied population of Baird's beaked whales came close to the coast -- within four km from land, and they were observed in shallow water; less than 300 meters.

"It is uncharacteristic for this species," says Olga Filatova, who also points out that the population likely has adapted to this particular habitat and thus deviates from the established perception that all beaked whales roam far out at sea and in deep waters.

"It means that you cannot expect all individuals within a specific species to behave the same way. This makes it difficult to plan species protection -- in this case, for example, you cannot plan based on the assumption that beaked whales only live far out in deep sea. We have shown that they can also live in shallow and coastal waters. There may be other different habitats that we are not aware of yet," says Olga Filatova.

There are many examples of individuals from the same whale species not behaving the same. In the whale world, it is common to find groups of the same species living in different places, eating different prey, communicating differently, and not liking to mingle with fellow species in other groups.

Some killer whale groups only hunt marine mammals like seals and porpoises, others only herring. Some humpback whales migrate between the tropics and the Arctic, others are residents in certain areas. Some sperm whale groups develop their own dialects for internal communication and do not like to communicate with others outside the group.

According to Olga Filatova, social learning is at play when groups develop preferences for, for example, habitats and prey.

There are many forms of social learning in the animal world. Imitation is the most complex form; the animal sees what others do and understands the motivation and reasoning behind it. Then there is "local enhancement," where an animal sees another animal heading to a specific place, follows, and learns that the place has value. This has been observed in many animals, including fish.

Olga Filatova believes that the population of Baird's beaked whales at the Commander Islands learns through "local enhancement": They see that some peers go to the shallow water near the coast, follow, and discover that it is a good place, probably because there are many fish.

"It becomes a cultural tradition, and it is the first time a cultural tradition has been observed among beaked whales," she says.

Other examples of cultural traditions in whales include when they develop specific hunting traditions: some slap their tails to stun fish, some generate waves to wash seals off ice floes, some chase fish onto the beach.

The researchers observed a total of 186 individuals of the Baird's beaked whale species at the Commander Islands from 2008-2019. 107 were only observed once and thus assessed to be transient whales. 79 individuals were spotted for more than one year and were thus assessed to be residents.

61 of the transient whales were seen interacting with the residents, and seven of them were seen in shallow water.

"The transients are not as familiar with local conditions as the residents, and therefore, they usually seek food at the depths that are normal for their species. But we actually observed some transients in the shallow area. These were individuals who had some form of social contact with the residents. It must be in that contact that they learned about the shallow water and its advantages," says Olga Filatova.

It is unclear how many Baird's beaked whales exist in the world.

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A long, long time ago in a galaxy not so far away

Employing massive data sets collected through NASA's James Webb Space Telescope, a research team led by a Rutgers University-New Brunswick astronomer is unearthing clues to conditions existing in the early universe.

The team has catalogued the ages of stars in the Wolf-Lundmark-Melotte (WLM) galaxy, constructing the most detailed picture of it yet, according to the researchers. WLM, a neighbor of the Milky Way, is an active center of star formation that includes ancient stars formed 13 billion years ago.

"In looking so deeply and seeing so clearly, we've been able to, effectively, go back in time," said Kristen McQuinn, an assistant professor in the Department of Physics and Astronomy in the School of Arts and Sciences, who led the research, described in the Astrophysical Journal. "You're basically going on a kind of archaeological dig, to find the very low mass stars that were formed early in the history of the universe."

McQuinn credited the Amarel high performance computing cluster managed by the Rutgers Office of Advanced Research Computing for enabling the team to calculate the galaxy's history of stellar development. One aspect of the research involved taking one massive calculation and repeating it 600 times, McQuinn said.

The major computation effort also helped confirm telescope calibrations and data processing procedures that will benefit the wider scientific community, she added.

So-called "low mass" galaxies are of special interest to McQuinn. Because they are believed to have dominated the early universe, they allow researchers to study the formation of stars, the evolution of chemical elements and the impact of star formation on the gas and structure of a galaxy. Faint and spread across the sky, they constitute the majority of galaxies in the local universe. Advanced telescopes such as the Webb are allowing scientists a closer look.

WLM -- an "irregular" galaxy, meaning it doesn't possess a distinct shape, such as a spiral or ellipse -- was discovered by the German astronomer Max Wolf in 1909 and characterized in greater detail in 1926 by Swedish astronomer Knut Lundmark and British astronomer Philibert Jacques Melotte. It is positioned at the outskirts of the Local Group, a dumbbell-shaped group of galaxies that includes the Milky Way.

Being at the edge of the Local Group has protected WLM from the ravages of intermingling with other galaxies, leaving its star population in a pristine state and useful for study, McQuinn noted. WLM also is interesting to astronomers because it is a dynamic, complex system with lots of gas, enabling it to actively form stars.

To formulate the galaxy's star formation history -- the rate at which stars have been born across different epochs of time in the universe -- McQuinn and her team employed the telescope to painstakingly zero in on swaths of sky containing hundreds of thousands of individual stars. To determine the age of a star, they measured its color -- a proxy for temperature -- and its brightness.

"We can use what we know about stellar evolution and what these colors and brightnesses indicate to basically age the galaxy's stars," said McQuinn, adding the researchers then counted the stars of different ages and mapped out the birth rate of stars over the history of the universe. "What you end up with is a sense of how old this structure is that you're looking at."

Cataloging the stars in this way showed the researchers that WLM's star producing abilities ebbed and flowed over time. The team's observations, which confirm earlier assessments by scientists using the Hubble Space Telescope, show that the galaxy produced stars early in the history of the universe over a period of 3 billion years. It paused for a while, then re-ignited.

McQuinn said she believes that the pause was caused by conditions specific to the early universe.

"The universe back then was really hot," she said. "We think the temperature of the universe ended up heating the gas in this galaxy, and kind of turned off star formation for a while. The cool down period lasted a few billion years and then star formation proceeded again."

The research is part of NASA's Early Release Program, where designated scientists work with the Space Telescope Science Institute and conduct research designed to highlight Webb's capabilities and help astronomers prepare for future observations.

NASA launched the Webb telescope in December 2021. The large-mirrored instrument orbits the sun a million miles away from Earth. Scientists compete for time on the telescope to study a host of topics including the conditions of the early universe, the history of the solar system, and the search for exoplanets.

"There's a lot of science that's going to come out of this program that hasn't been done yet," McQuinn said.

Read more at Science Daily

Greenhouse gas repurposed

Cutting-edge University of Auckland research converted waste carbon dioxide into a potential precursor for chemicals and carbon-free fuel.

Dr Ziyun Wang's researchers in the School of Chemical Sciences, in collaboration with researchers at Chinese institutions, have demonstrated a method for turning CO2 into formic acid, reported in the journal Nature.

In benchtop experiments, a catalyst made from waste lead-acid batteries enabled a transformation which hadn't been possible using previous catalysts.

Formic acid -- the same substance produced by ants (formica is the Latin word for ant) -- is a colourless and pungent liquid with potential as a transportation fuel, for storing electrical energy and for enabling the petrochemical industry to cut CO2 emissions.

As emissions of carbon dioxide, the primary greenhouse gas, rise each year, scientists are looking into options for the capture and storage of CO2, for repurposing CO2, and for pursuing a carbon-free economy.

Wang's group is one of the world leaders in research into CO2 electrochemical reduction (CO2RR) using acidic rather than alkaline conditions.

"This innovation opens up exciting possibilities for carbon-neutral technologies," he says.

"In the future, cars and gas stations could be using repurposed carbon dioxide."

In tests, the new method efficiently converted CO2. for more than 5,000 hours, and the researchers' calculations suggest it can be cost-effectively scaled up for industry.

The experiments used a proton exchange membrane electrolyser.

Carbon dioxide flowed into an electrochemical cell and was converted into formic acid, just like charging a battery.

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Scandinavia's first farmers slaughtered the hunter-gatherer population, study finds

Following the arrival of the first farmers in Scandinavia 5,900 years ago, the hunter-gatherer population was wiped out within a few generations, according to a new study from Lund University in Sweden, among others. The results, which are contrary to prevailing opinion, are based on DNA analysis of skeletons and teeth found in what is now Denmark.

The extensive study has been published as four separate articles in the journal Nature. An international research team, of which Lund University in Sweden is a member, has been able to draw new conclusions about the effects of migration on ancient populations by extracting DNA from skeletal parts and teeth of prehistoric people.

The study shows, among other things, that there have been two almost total population turnovers in Denmark over the past 7,300 years.

The first population change happened 5,900 years ago when a farmer population, with a different origin and appearance, drove out the gatherers, hunters and fishers who had previously populated Scandinavia.

Within a few generations, almost the entire hunter-gatherer population was wiped out.

"This transition has previously been presented as peaceful. However, our study indicates the opposite. In addition to violent death, it is likely that new pathogens from livestock finished off many gatherers," says Anne Birgitte Nielsen, geology researcher and head of the Radiocarbon Dating Laboratory at Lund University.

A thousand years later, about 4,850 years ago, another population change took place when people with genetic roots in Yamnaya -- a livestock herding people with origins in southern Russia -- came to Scandinavia and wiped out the previous farmer population.

Once again, this could have involved both violence and new pathogens.

These big-boned people pursued a semi-nomadic life on the steppes, tamed animals, kept domestic cattle and moved over large areas using horses and carts.

The people who settled in our climes were a mix between Yamnaya and Eastern European Neolithic people.

This genetic profile is dominant in today's Denmark, whereas the DNA profile of the first farmer population has been essentially erased.

"This time there was also a rapid population turnover, with virtually no descendants from the predecessors. We don't have as much DNA material from Sweden, but what there is points to a similar course of events. In other words, many Swedes are to a great extent also descendants of these semi-nomads," says Anne Birgitte Nielsen, who contributed quantitative pollen data which shows how the vegetation changed in connection with the population changes.

The results do not just overturn previous theories about amorous and peaceful meetings between groups of people.

The study also provides a deepened understanding of historical migration flows, and the interpretation of archaeological finds and changes in vegetation and land use found in palaeoecological data.

"Our results help to enhance our knowledge of our heredity and our understanding of the development of certain diseases. Something that in the long term could be beneficial, for example in medical research," concludes Anne Birgitte Nielsen.

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Ice cores provide first documentation of rapid Antarctic ice loss in the past

Researchers from the University of Cambridge and the British Antarctic Survey have uncovered the first direct evidence that the West Antarctic Ice Sheet shrunk suddenly and dramatically at the end of the Last Ice Age, around eight thousand years ago.

The evidence, contained within an ice core, shows that in one location the ice sheet thinned by 450 metres -- that's more than the height of the Empire State Building -- in just under 200 years.

This is the first evidence anywhere in Antarctica for such a fast loss of ice. Scientists are worried that today's rising temperatures might destabilize parts of the West Antarctic Ice Sheet in the future, potentially passing a tipping point and inducing a runaway collapse. The new study, published in Nature Geoscience, sheds light on how quickly Antarctic ice could melt if temperatures continue to soar.

"We now have direct evidence that this ice sheet suffered rapid ice loss in the past," said Professor Eric Wolff, senior author of the new study from Cambridge's Department of Earth Sciences. "This scenario isn't something that exists only in our model predictions and it could happen again if parts of this ice sheet becomes unstable."

The Antarctic ice sheets, from west to east, contain enough freshwater to raise global sea levels by around 57 metres. The West Antarctic Ice Sheet is considered particularly vulnerable because much of it sits on bedrock that lies below sea level.

Model predictions suggest that a large part of the West Antarctic Ice Sheet could disappear in the next few centuries, causing sea levels to rise. Exactly when and how quickly the ice could be lost is, however, uncertain.

One way to train ice sheet models to make better predictions is to feed them with data on ice loss from periods of warming in Earth's history. At the peak of Last Ice Age 20,000 years ago, Antarctic ice covered a larger area than today. As our planet thawed and temperatures slowly climbed, the West Antarctic Ice Sheet contracted to more or less its current extent.

"We wanted to know what happened to the West Antarctic Ice Sheet at the end of the Last Ice Age, when temperatures on Earth were rising, albeit at a slower rate than current anthropogenic warming," said Dr Isobel Rowell, study co-author from the British Antarctic Survey. "Using ice cores we can go back to that time and estimate the ice sheet's thickness and extent."

Ice cores are made up of layers of ice that formed as snow fell and was then buried and compacted into ice crystals over thousands of years. Trapped within each ice layer are bubbles of ancient air and contaminants that mixed with each year's snowfall -- providing clues as to the changing climate and ice extent.

The researchers drilled a 651-metre-long ice core from Skytrain Ice Rise in 2019. This mound of ice sits at the edge of the ice sheet, near the point where grounded ice flows into the floating Ronne Ice Shelf.

After transporting the ice cores back to Cambridge at -20oC, the researchers analysed them to reconstruct the ice thickness. First, they measured stable water isotopes, which indicate the temperature at the time the snow fell. Temperature decreases at higher altitudes (think of cold mountain air), so they were able to equate warmer temperatures with lower-lying, thinner ice.

They also measured the pressure of air bubbles trapped in the ice. Like temperature, air pressure also varies systematically with elevation. Lower-lying, thinner ice contains higher pressure air bubbles.

These measurements told them that ice thinned rapidly 8,000 years ago. "Once the ice thinned, it shrunk really fast," said Wolff, "this was clearly a tipping point -- a runaway process."

They think this thinning was probably triggered by warm water getting underneath the edge of the West Antarctic Ice Sheet, which normally sits on bedrock. This likely untethered a section of the ice from bedrock, allowing it to float suddenly and forming what is now the Ronne Ice Shelf. This then allowed neighbouring Skytrain Ice Rise, no longer restrained by grounded ice, to thin rapidly.

The researchers also found that the sodium content of the ice (originating from salt in sea spray) increased about 300 years after the ice thinned. This told them that, after the ice thinned, the ice shelf shrunk back so that the sea was hundreds of kilometres nearer to their site.

"We already knew from models that the ice thinned at around this time, but the date of this was uncertain," said Rowell. Ice sheet models placed the retreat anywhere between 12,000 and 5,000 years ago and couldn't say how quickly it happened. "We now have a very precisely dated observation of that retreat which can be built into improved models," said Rowell.

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Mimas' surprise: Tiny moon of Saturn holds young ocean beneath icy shell

Hidden beneath the heavily cratered surface of Mimas, one of Saturn's smallest moons, lies a secret: a global ocean of liquid water. This astonishing discovery, led by Dr. Valéry Lainey of the Observatoire de Paris-PSL and published in the journal Nature, reveals a "young" ocean formed just 5 to 15 million years ago, making Mimas a prime target for studying the origins of life in our Solar System.

"Mimas is a small moon, only about 400 kilometers in diameter, and its heavily cratered surface gave no hint of the hidden ocean beneath," says Dr Nick Cooper, a co-author of the study and Honorary Research Fellow in the Astronomy Unit of the School of Physical and Chemical Sciences at Queen Mary University of London.

"This discovery adds Mimas to an exclusive club of moons with internal oceans, including Enceladus and Europa, but with a unique difference: its ocean is remarkably young, estimated to be only 5 to 15 million years old."

This young age, determined through detailed analysis of Mimas's tidal interactions with Saturn, suggests the ocean formed recently, based on the discovery of an unexpected irregularity in its orbit.

As a result, Mimas provides a unique window into the early stages of ocean formation and the potential for life to emerge.

"The existence of a recently formed liquid water ocean makes Mimas a prime candidate for study, for researchers investigating the origin of life," explains Dr Cooper.

The discovery was made possible by analysing data from NASA's Cassini spacecraft, which meticulously studied Saturn and its moons for over a decade.

By closely examining the subtle changes in Mimas's orbit, the researchers were able to infer the presence of a hidden ocean and estimate its size and depth.

Dr Cooper continues: "This has been a great team effort, with colleagues from five different institutions and three different countries coming together under the leadership of Dr Valéry Lainey to unlock another fascinating and unexpected feature of the Saturn system, using data from the Cassini mission."

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Inexpensive, carbon-neutral biofuels are finally possible

When it comes to making fuel from plants, the first step has always been the hardest -- breaking down the plant matter. A new study finds that introducing a simple, renewable chemical to the pretreatment step can finally make next-generation biofuel production both cost-effective and carbon neutral.

For biofuels to compete with petroleum, biorefinery operations must be designed to better utilize lignin. Lignin is one of the main components of plant cell walls. It provides plants with greater structural integrity and resiliency from microbial attacks. However, these natural properties of lignin also make it difficult to extract and utilize from the plant matter, also known as biomass.

"Lignin utilization is the gateway to making what you want out of biomass in the most economical and environmentally friendly way possible," said UC Riverside Associate Research Professor Charles Cai. "Designing a process that can better utilize both the lignin and sugars found in biomass is one of the most exciting technical challenges in this field."

To overcome the lignin hurdle, Cai invented CELF, which stands for co-solvent enhanced lignocellulosic fractionation. It is an innovative biomass pretreatment technology.

"CELF uses tetrahydrofuran or THF to supplement water and dilute acid during biomass pretreatment. It improves overall efficiency and adds lignin extraction capabilities," Cai said. "Best of all, THF itself can be made from biomass sugars."

A landmark Energy & Environmental Science paper details the degree to which a CELF biorefinery offers economic and environmental benefits over both petroleum-based fuels and earlier biofuel production methods.

The paper is a collaboration between Cai's research team at UCR, the Center for Bioenergy Innovation managed by Oak Ridge National Laboratories, and the National Renewable Energy Laboratory, with funding provided by the U.S. Department of Energy's Office of Science. In it, the researchers consider two main variables: what kind of biomass is most ideal and what to do with the lignin once it's been extracted.

First-generation biofuel operations use food crops like corn, soy, and sugarcane as raw materials, or feedstocks. Because these feedstocks divert land and water away from food production, using themfor biofuels is not ideal.

Second-generation operations use non-edible plant biomass as feedstocks. An example of biomass feedstocks includes wood residues from milling operations, sugarcane bagasse, or corn stover, all of which are abundant low-cost byproducts of forestry and agricultural operations.

According to the Department of Energy, up to a billion tons per year of biomass could be made available for the manufacture of biofuels and bioproducts in the US alone, capable of displacing 30% of our petroleum consumption while also creating new domestic jobs.

Because a CELF biorefinery can more fully utilize plant matter than earlier second-generation methods, the researchers found that a heavier, denser feedstock like hardwood poplar is preferable over less carbon-dense corn stover for yielding greater economic and environmental benefits.

Using poplar in a CELF biorefinery, the researchers demonstrate that sustainable aviation fuel could be made at a break-even price as low as $3.15 per gallon of gasoline equivalent. The current average cost for a gallon of jet fuel in the U.S. is $5.96.

The U.S. government issues credits for biofuel production in the form of renewable identification number credits, a subsidy meant to bolster domestic biofuel production. The tier of these credits issued for second-generation biofuels, the D3 tier, is typically traded at $1 per gallon or higher. At this price per credit, the paper demonstrates that one can expect a rate of return of over 20% from the operation.

"Spending a little more for a more carbon-rich feedstock like poplar still yields more economic benefits than a cheaper feedstock like corn stover, because you can make more fuel and chemicals from it," Cai said.

The paper also illustrates how lignin utilization can positively contribute to overall biorefinery economics while keeping the carbon footprint as low as possible. In older biorefinery models, where biomass is cooked in water and acid, the lignin is mostly unusable for more than its heating value.

"The older models would elect to burn the lignin to supplement heat and energy for these biorefineries because they could mostly only leverage the sugars in the biomass -- a costly proposition that leaves a lot of value off the table," said Cai.

In addition to better lignin utilization, the CELF biorefinery model also proposes to produce renewable chemicals. These chemicals could be used as building blocks for bioplastics and food and drink flavoring compounds. These chemicals take up some of the carbon in the plant biomass that would not get released back into the atmosphere as CO2.

"Adding THF helps reduce the energy cost of pretreatment and helps isolate lignin, so you wouldn't have to burn it anymore. On top of that, we can make renewable chemicals that help us achieve a near-zero global warming potential," Cai said. "I think this moves the needle from Gen 2 biofuels to Gen 2+."

In light of the team's recent successes, the Department of Energy's Bioenergy Technology Office has awarded the researchers a $2 million grant to build a small-scale CELF pilot plant at UCR. Cai hopes that demonstrating the pilot plant will lead to larger-scale investment in the technology, as harnessing energy from fossil fuels adds to global warming and hurts the planet.

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What turned Earth into a giant snowball 700m years ago? Scientists now have an answer

Australian geologists have used plate tectonic modelling to determine what most likely caused an extreme ice-age climate in Earth's history, more than 700 million years ago.

The study, published in Geology, helps our understanding of the functioning of the Earth's built-in thermostat that prevents the Earth from getting stuck in overheating mode.

It also shows how sensitive global climate is to atmospheric carbon concentration.

"Imagine the Earth almost completely frozen over," said the study's lead author, ARC Future Fellow Dr Adriana Dutkiewicz.

"We now think we have cracked the mystery: historically low volcanic carbon dioxide emissions, aided by weathering of a large pile of volcanic rocks in what is now Canada; a process that absorbs atmospheric carbon dioxide."

The project was inspired by the glacial debris left by the ancient glaciation from this period that can be spectacularly observed in the Flinders Ranges in South Australia.

A recent geological field trip to the Ranges, led by co-author Professor Alan Collins from the University of Adelaide, prompted the team to use the University of Sydney EarthByte computer models to investigate the cause and the exceptionally long duration of this ice age.

The extended ice age, also called the Sturtian glaciation after the 19th century European colonial explorer of central Australia, Charles Sturt, stretched from 717 to 660 million years ago, a period well before the dinosaurs and complex plant life on land existed.

Dr Dutkiewicz said: "Various causes have been proposed for the trigger and the end of this extreme ice age, but the most mysterious aspect is why it lasted for 57 million years -- a time span hard for us humans to imagine."

The team went back to a plate tectonic model that shows the evolution of continents and ocean basins at a time after the breakup of the ancient supercontinent Rodina.

They connected it to a computer model that calculates CO2 degassing of underwater volcanoes along mid-ocean ridges -- the sites where plates diverge and new ocean crust is born.

They soon realised that the start of the Sturtian ice age precisely correlates with an all-time low in volcanic CO2 emissions.

In addition, the CO2 outflux remained relatively low for the entire duration of the ice age.

Dr Dutkiewicz said: "At this time, there were no multicellular animals or land plants on Earth. The greenhouse gas concentration of the atmosphere was almost entirely dictated by CO2 outgassing from volcanoes and by silicate rock weathering processes, which consume CO2."

Co-author Professor Dietmar Müller from the University of Sydney said: "Geology ruled climate at this time. We think the Sturtian ice age kicked in due to a double whammy: a plate tectonic reorganisation brought volcanic degassing to a minimum, while simultaneously a continental volcanic province in Canada started eroding away, consuming atmospheric CO2.

"The result was that atmospheric CO2 fell to a level where glaciation kicks in -- which we estimate to be below 200 parts per million, less than half today's level."

The team's work raises intriguing questions about Earth's long-term future.

A recent theory proposed that over the next 250 million years, Earth would evolve towards Pangea Ultima, a supercontinent so hot that mammals might become extinct.

However, the Earth is also currently on a trajectory of lower volcanic CO2 emissions, as continental collisions increase and the plates slow down.

Read more at Science Daily

Using cancer's strength to fight against it

Scientists at the UC San Francisco (UCSF) and Northwestern Medicine may have found a way around the limitations of engineered T cells by borrowing a few tricks from cancer itself.

By studying mutations in malignant T cells that cause lymphoma, they zeroed in on one that imparted exceptional potency to engineered T cells.

Inserting a gene encoding this unique mutation into normal human T cells made them more than 100 times more potent at killing cancer cells without any signs of becoming toxic.

While current immunotherapies work only against cancers of the blood and bone marrow, the T cells engineered by Northwestern and UCSF were able to kill tumors derived from skin, lung and stomach in mice.

The team has already begun working toward testing this new approach in people.

"We used nature's roadmap to make better T cell therapies," said Dr. Jaehyuk Choi, an associate professor of dermatology and of biochemistry and molecular genetics at Northwestern University Feinberg School of Medicine.

"The superpower that makes cancer cells so strong can be transferred into T cell therapies to make them powerful enough to eliminate what were once incurable cancers."

"Mutations underlying the resilience and adaptability of cancer cells can super-charge T cells to survive and thrive in the harsh conditions that tumors create," said Kole Roybal, associate professor of microbiology and immunology at UCSF, center director for the Parker Institute for Cancer Immunotherapy Center at UCSF, and a member of the Gladstone Institute of Genomic Immunology.

The study will appear in Nature Feb. 7.

A solution hiding in plain sight

Creating effective immunotherapies has proven difficult against most cancers because the tumor creates an environment focused on sustaining itself, redirecting resources like oxygen and nutrients for its own benefit.

Often, tumors hijack the body's immune system, causing it to defend the cancer, instead of attacking it.

Not only does this impair the ability of regular T cells to target cancer cells, it undermines the effectiveness of the engineered T cells that are used in immunotherapies, which quickly tire against the tumor's defenses.

"For cell-based treatments to work under these conditions," Roybal said, "we need to give healthy T cells abilities that are beyond what they can naturally achieve."

The Northwestern and UCSF teams screened 71 mutations found in patients with T cell lymphoma and identified which ones could enhance engineered T cell therapies in mouse tumor models.

Eventually, they isolated one that proved both potent and non-toxic, subjecting it to a rigorous set of safety tests.

"Our discoveries empower T cells to kill multiple cancer types," said Choi, a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

"This approach performs better than anything we've seen before." Their discoveries can be incorporated into treatments for many types of cancer, the scientists said.

"T cells have the potential to offer cures to people who are heavily pretreated and have a poor prognosis," Choi said.

"Cell therapies are living drugs, because they live and grow inside the patient and can provide long-term immunity against cancer."

In collaboration with the Parker Institute for Cancer Immunotherapy and Venrock, Roybal and Choi are building a new company, Moonlight Bio, to realize the potential of their groundbreaking approach.

They are currently developing a cancer therapy that they hope to begin testing in people within the next few years.

"We see this as the starting point," Roybal said. "There's so much to learn from nature about how we can enhance these cells and tailor them to different types of diseases."

Read more at Science Daily

Which came first: Black holes or galaxies?

Black holes not only existed at the dawn of time, they birthed new stars and supercharged galaxy formation, a new analysis of James Webb Space Telescope data suggests.

The insights upend theories of how black holes shape the cosmos, challenging classical understanding that they formed after the first stars and galaxies emerged.

Instead, black holes might have dramatically accelerated the birth of new stars during the first 50 million years of the universe, a fleeting period within its 13.8 billion -- year history.

"We know these monster black holes exist at the center of galaxies near our Milky Way, but the big surprise now is that they were present at the beginning of the universe as well and were almost like building blocks or seeds for early galaxies," said lead author Joseph Silk, a professor of physics and astronomy at Johns Hopkins University and at Institut of Astrophysics, Paris, Sorbonne University.

"They really boosted everything, like gigantic amplifiers of star formation, which is a whole turnaround of what we thought possible before -- so much so that this could completely shake up our understanding of how galaxies form."

The work is newly published in the Astrophysical Journal Letters.

Distant galaxies from the very early universe, observed through the Webb telescope, appear much brighter than scientists predicted and reveal unusually high numbers of young stars and supermassive black holes, Silk said.

Conventional wisdom holds that black holes formed after the collapse of supermassive stars and that galaxies formed after the first stars lit up the dark early universe.

But the analysis by Silk's team suggests that black holes and galaxies coexisted and influenced each other's fate during the first 100 million years.

If the entire history of the universe were a 12-month calendar, those years would be like the first days of January, Silk said.

"We're arguing that black hole outflows crushed gas clouds, turning them into stars and greatly accelerating the rate of star formation," Silk said.

"Otherwise, it's very hard to understand where these bright galaxies came from because they're typically smaller in the early universe. Why on earth should they be making stars so rapidly?"

Black holes are regions in space where gravity is so strong that nothing can escape their pull, not even light.

Because of this force, they generate powerful magnetic fields that make violent storms, ejecting turbulent plasma and ultimately acting like enormous particle accelerators, Silk said.

This process, he said, is likely why Webb's detectors have spotted more of these black holes and bright galaxies than scientists anticipated.

"We can't quite see these violent winds or jets far, far away, but we know they must be present because we see many black holes early on in the universe," Silk explained.

"These enormous winds coming from the black holes crush nearby gas clouds and turn them into stars. That's the missing link that explains why these first galaxies are so much brighter than we expected."

Silk's team predicts the young universe had two phases. During the first phase, high-speed outflows from black holes accelerated star formation, and then, in a second phase, the outflows slowed down.

A few hundred million years after the big bang, gas clouds collapsed because of supermassive black hole magnetic storms, and new stars were born at a rate far exceeding that observed billions of years later in normal galaxies, Silk said.

The creation of stars slowed down because these powerful outflows transitioned into a state of energy conservation, he said, reducing the gas available to form stars in galaxies.

"We thought that in the beginning, galaxies formed when a giant gas cloud collapsed," Silk explained.

"The big surprise is that there was a seed in the middle of that cloud -- a big black hole -- and that helped rapidly turn the inner part of that cloud into stars at a rate much greater than we ever expected. And so the first galaxies are incredibly bright."

The team expects future Webb telescope observations, with more precise counts of stars and supermassive black holes in the early universe, will help confirm their calculations.

Silk expects these observations will also help scientists piece together more clues about the evolution of the universe.

"The big question is, what were our beginnings? The sun is one star in 100 billion in the Milky Way galaxy, and there's a massive black hole sitting in the middle, too. What's the connection between the two?" he said.

"Within a year we'll have so much better data, and a lot of our questions will begin to get answers."

Read more at Science Daily

In a warming world, climate scientists consider category 6 hurricanes

For more than 50 years, the National Hurricane Center has used the Saffir-Simpson Windscale to communicate the risk of property damage; it labels a hurricane on a scale from Category 1 (wind speeds between 74 -- 95 mph) to Category 5 (wind speeds of 158 mph or greater).

But as increasing ocean temperatures contribute to ever more intense and destructive hurricanes, climate scientists Michael Wehner of Lawrence Berkeley National Laboratory (Berkeley Lab) and James Kossin of the First Street Foundation wondered whether the open-ended Category 5 is sufficient to communicate the risk of hurricane damage in a warming climate.

So they investigated and detailed their extensive research in a new article published in the Proceedings of the National Academy of Sciences (PNAS), where they also introduce a hypothetical Category 6 to the Saffir-Simpson Wind Scale, which would encompass storms with wind speeds greater than 192 mph.

"Our motivation is to reconsider how the open-endedness of the Saffir-Simpson Scale can lead to underestimation of risk, and, in particular, how this underestimation becomes increasingly problematic in a warming world," said Wehner, who has spent his career studying the behavior of extreme weather events in a changing climate and to what extent human influence has contributed to individual events.

According to Wehner, anthropogenic global warming has significantly increased surface ocean and tropospheric air temperatures in regions where hurricanes, tropical cyclones, and typhoons form and propagate, providing additional heat energy for storm intensification.

When the team performed a historical data analysis of hurricanes from 1980 to 2021, they found five storms that would have been classified as Category 6, and all of them occurred in the last nine years of record.

They determined a hypothetical upper bound for Category 5 hurricanes by looking at the expanding range of wind speeds between the lower-category storms.

Hurricanes, tropical storms, and typhoons are essentially the same weather phenomenon; their name difference is purely geographical: storms in the North Atlantic and Northeast Pacific Oceans are called hurricanes, events in the Northwest Pacific Ocean are called typhoons, and occurrences in the South Pacific and Indian Oceans are called tropical cyclones.

In addition to studying the past, the researchers analyzed simulations to explore how warming climates would impact hurricane intensification.

Their models showed that with two degrees Celsius of global warming above pre-industrial levels, the risk of Category 6 storms increases by up to 50% near the Philippines and doubles in the Gulf of Mexico and that the highest risk of these storms is in Southeast Asia, the Philippines, and the Gulf of Mexico.

"Even under the relatively low global warming targets of the Paris Agreement, which seeks to limit global warming to just 1.5°C above preindustrial temperatures by the end of this century, the increased chances of Category 6 storms are substantial in these simulations," said Wehner.

Read more at Science Daily

How a city is organized can create less-biased citizens

The city you live in could be making you, your family, and your friends more unconsciously racist. Or, your city might make you less racist. It depends on how populous, diverse, and segregated your city is, according to a new study that brings together the math of cities with the psychology of how individuals develop unconscious racial biases.

The study, published in the latest issue of Nature Communications, presents data and a mathematical model of exposure and adaptation in social networks that can help explain why there is more unconscious, or implicit, racial bias in some cities than others.

The authors hope that local communities and governments can use the findings to help create more just and equitable cities.

"What I think is most interesting is the implication that there's a piece of systemic racism that has to do with how people learn and the way cities are organized," says psychologist Andrew Stier, an SFI Complexity Postdoctoral Fellow and lead author of the study.

Cities create dense networks of social interaction between people.

Because of the interactions with many different people, we need to be constantly adapting to new situations and learning, explains SFI External Professor Luís Bettencourt(University of Chicago), a co-leader of SFI's Cities, Scaling and Sustainability project and co-author of the study.

To see how racial biases emerge from how U.S. cities are organized, Stier turned to the enormous database of the Implicit Association Test (IAT). In the popular online test, volunteer participants are given a pairing of White or Black faces with positive or negative words and asked to categorize a single face or word.

If they are faster to categorize things when White/good are paired they have a White-good bias and if they are faster to categorize things when Black/good are paired they have a Black-good bias.

"People may feel they are not prejudiced, but can unconsciously have a preference for one group or another, and this is revealed by these tests," Stier says.

The researchers took the average IAT bias scores from approximately 2.7 million individuals in different geographic areas and linked them to racial demographics and population data from the U.S. Census to build a model that accounts for how individuals learn biases through their social networks.

They found that when these networks are larger, more diverse, and less segregated in cities, implicit racial biases decrease.

The results suggest that there are structural reasons why cities help or deter people from becoming less racially biased.

Perhaps the most pronounced reason is the segregation of different racial groups into different neighborhoods.

Related to that is the lack of more cosmopolitan public spaces where a diverse range of people can experience positive interactions with one another.

Read more at Science Daily

EVs that go 1,000 km on a single charge: Gel makes it possible

Futuristic advancements in AI and healthcare stole the limelight at the tech extravaganza Consumer Electronics Show (CES) 2024. However, battery technology is the game-changer at the heart of these innovations, enabling greater power efficiency. Importantly, electric vehicles are where this technology is being applied most intensely. Today's EVs can travel around 700km on a single charge, while researchers are aiming for a 1,000km battery range. Researchers are fervently exploring the use of silicon, known for its high storage capacity, as the anode material in lithium-ion batteries for EVs. However, despite its potential, bringing silicon into practical use remains a puzzle that researchers are still working hard to piece together.

Enter Professor Soojin Park, PhD candidate Minjun Je, and Dr. Hye Bin Son from the Department of Chemistry at Pohang University of Science and Technology (POSTECH). They have cracked the code, developing a pocket-friendly and rock-solid next-generation high-energy-density Li-ion battery system using micro silicon particles and gel polymer electrolytes.

This work was published on the online pages of Advanced Science on the 17th of January.

Employing silicon as a battery material presents challenges: It expands by more than three times during charging and then contracts back to its original size while discharging, significantly impacting battery efficiency.

Utilizing nano-sized silicon (10-9m) partially addresses the issue, but the sophisticated production process is complex and astronomically expensive, making it a challenging budget proposition.

By contrast, micro-sized silicon (10-6m) is superbly practical in terms of cost and energy density.

Yet, the expansion issue of the larger silicon particles becomes more pronounced during battery operation, posing limitations for its use as an anode material.

The research team applied gel polymer electrolytes to develop an economical yet stable silicon-based battery system.

The electrolyte within a lithium-ion battery is a crucial component, facilitating the movement of ions between the cathode and anode.

Unlike conventional liquid electrolytes, gel electrolytes exist in a solid or gel state, characterized by an elastic polymer structure that has better stability than their liquid counterparts do.

The research team employed an electron beam to form covalent linkages between micro-silicon particles and gel electrolytes.

These covalent linkages serve to disperse internal stress caused by volume expansion during lithium-ion battery operation, alleviating the changes in micro silicon volume and enhancing structural stability.

The outcome was remarkable: The battery exhibited stable performance even with micro silicon particles (5μm), which were a hundred times larger than those used in traditional nano-silicon anodes.

Additionally, the silicon-gel electrolyte system developed by the research team exhibited ion conductivity similar to conventional batteries using liquid electrolytes, with an approximate 40% improvement in energy density.

Moreover, the team's system holds significant value due to its straightforward manufacturing process that is ready for immediate application.

Professor Soojin Park stressed: "We used a micro-silicon anode, yet, we have a stable battery. This research brings us closer to a real high-energy-density lithium-ion battery system."

Read more at Science Daily

Gas on the run -- ALMA spots the shadow of a molecular outflow from a quasar when the Universe was less than one billion years old

Theoretical predictions have been confirmed with the discovery of an outflow of molecular gas from a quasar when the Universe was less than a billion years old.

A quasar is a compact region powered by a supermassive black hole located in the center of a massive galaxy.

They are extremely luminous, with a point-like appearance similar to stars, and are extremely distant from Earth.

Owing to their distance and brightness, they provide a peek into conditions of the early Universe, when it was less than 1 billion years old.

A team of researchers led by Assistant Professor Dragan Salak at Hokkaido University, Assistant Professor Takuya Hashimoto at the University of Tsukuba, and Professor Akio Inoue at Waseda University, has discovered the first evidence of suppression of star formation driven by an outflow of molecular gas in a quasar-host galaxy in the early Universe.

Their findings, based on observations they made using the Atacama Large Millimeter/submillimeter Array (ALMA), in Chile, were published in The Astrophysical Journal.

Molecular gas is vital to the formation of stars. As the primary fuel of star formation, the ubiquity and high concentrations of molecular gas within a galaxy would lead to a vast number of stars being formed.

By ejecting this gas into intergalactic space faster than it could be consumed by star formation, molecular outflows effectively suppress the formation of stars in galaxies that host quasars.

"Theoretical work suggests that molecular gas outflows play an important role in the formation and evolution of galaxies from an early age, because they can regulate star formation," Salak explains.

"Quasars are especially energetic sources, so we expected that they may be able to generate powerful outflows."

The quasar the researchers observed, J2054-0005, has a very high redshift -- it and the Earth are apparently moving away from each other very fast.

"J2054-0005 is one of the brightest quasars in the distant Universe, so we decided to target this object as an excellent candidate to study powerful outflows," Hashimoto says.

The researchers used ALMA to observe the outflow of molecular gas from the quasar.

As the only telescope in the world that has the sensitivity and frequency coverage to detect molecular gas outflows in the early Universe, ALMA was key to this study.

Speaking about the method used in the study, Salak comments: "The outflowing molecular (OH) gas was discovered in absorption. This means we did not observe microwave radiation coming directly from the OH molecules; instead, we observed the radiation coming from the bright quasar -- and absorption means that OH molecules happened to absorb a part of the radiation from the quasar. So, it was like revealing the presence of a gas by seeing the 'shadow' it cast in front of the light source."

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Vitamin B12 adaptability in Antarctic algae has implications for climate change, life in the Southern Ocean

Vitamin B12 deficiency in people can cause a slew of health problems and even become fatal. Until now, the same deficiencies were thought to impact certain types of algae, as well. A new study examined the algae Phaeocystis antarctica's (P. antarctica) exposure to a matrix of iron and vitamin B12 conditions. Results show that this algae has the ability to survive without B12, something that computer analysis of genome sequences had incorrectly indicated.

The alga, native to the Southern Ocean, starts as a single-cell that can transform into millimeter scale colonies.

The research published in PNAS, "Flexible B12 ecophysiology of Phaeocystis antarctica due to a fusion B12-independent methionine synthase with widespread homologues," conducted by MIT, WHOI, J.C. Venter Institute, and Scripps Institution of Oceanography (UCSD), found that unlike other keystone polar phytoplankton, P. antarctica can survive with or without vitamin B12.

"Vitamin B12 is really important to the algae's metabolism and because it allows them to make a key amino acid more efficiently," said Makoto Saito, one of the study's co-authors and senior scientist at the Woods Hole Oceanographic Institution (WHOI). "When you can't get vitamin B12, life has ways to make those amino acids more slowly, causing them to grow slower as well. In this case, there's two forms of the enzyme that makes the amino acid methionine, one needing B12, and one that is much slower, but doesn't need B12. This means P. antarctica has the ability to adapt and survive with low B12 availability."

Researchers came to their conclusion by studying P. antarctica's proteins in a lab culture, and also searching for key proteins in field samples.

During their observation, they found the algae to have a B12-independent methionine synthase fusion protein (MetE). The MetE gene isn't new, but was previously believed not to have been possessed by P. antarctica. MetE gives the algae the flexibility to adapt to low vitamin B12 availability.

"This study suggests that the reality is more complex. For most algae, maintaining a flexible metabolism for B12 is beneficial, given how scarce the vitamin's supply is in seawater," said Deepa Rao, lead researcher of the study and former MIT postdoc." Having this flexibility enables them to make essential amino acids, even when they can't obtain enough of the vitamin from the environment. Implying that the classification of algae as B12-requiring or not might be too simplistic"

Antarctica, which lives at the base of the food web, has been thought to be entirely controlled by iron nutrition.

The discovery of the MetE gene also indicates vitamin B12 likely plays a factor.

Because of its presence in P. antarctica, the adaptability of the algae gives it a potential advantage to bloom in the early austral spring when the bacteria that produce B12, are scarcer.

This discovery also has implications for climate change. The Southern Ocean, where P. antarctica is found, plays a significant role in the Earth's carbon cycle.

P. antarctica takes in the CO2 and releases oxygen through photosynthesis.

"As our global climate warms, there's increasing amounts of iron entering the coastal Southern Ocean from melting glaciers," Saito said.

"Predicting what the next limiting thing after iron is important, and B12 appears to be one of them. Climate modelers want to know how much algae is growing in the ocean in order to get predictions right and they've parameterized iron, but haven't included B12 in those models yet."

"We are particularly interested in knowing more about the extent of strain level diversity. It will be interesting to see if B12 independent strains have a competitive advantage in a warmer Southern Ocean," said co-author of the study Andy Allen, a joint professor at the J. Craig Venter Institute and the Scripps Institution of Oceanography at the University of California, San Diego.

"Since there is a cost to B12 independence in terms of metabolic efficiency, an important question is whether or not strains that require B12 might become reliant on B12 producing bacteria."

Read more at Science Daily

World's largest childhood trauma study uncovers brain rewiring

The world's largest brain study of childhood trauma has revealed how it affects development and rewires vital pathways.

The University of Essex study -- led by the Department of Psychology's Dr Megan Klabunde -- uncovered a disruption in neural networks involved in self-focus and problem-solving.

This means under-18s who experienced abuse will likely struggle with emotions, empathy and understanding their bodies.

Difficulties in school caused by memory, hard mental tasks and decision making may also emerge.

Dr Klabunde's cutting-edge research used AI to re-examine hundreds of brain scans and identify patterns.

It is hoped the research will help hone new treatments for children who have endured mistreatment.

This could mean therapists focus on techniques that rewire these centres and rebuild their sense of self.

Dr Klabunde said: "Currently, science-based treatments for childhood trauma primarily focus on addressing the fearful thoughts and avoidance of trauma triggers.

"This is a very important part of trauma treatment. However, our study has revealed that we are only treating one part of the problem.

"Even when a child who has experienced trauma is not thinking about their traumatic experiences, their brains are struggling to process their sensations within their bodies.

"This influences how one thinks and feels about one's 'internal world' and this also influences one's ability to empathise and form relationships."

Dr Klabunde reviewed 14 studies involving more than 580 children for the research published in Biological Psychiatry Cognitive Neuroscience and Neuroimaging.

The paper re-examined functional magnetic resonance imaging (fMRI) scans.

This procedure highlights blood flow in different centres, showing neurological activity.

The study discovered a marked difference in traumatised children's default mode (DMN) and central executive networks (CEN) -- two large scale brain systems.

The DMN and the posterior insula are involved in how people sense their body, the sense of self and their internal reflections.

New studies are finding the DMN plays an important role in most mental health problems -- and may be influenced by experiencing childhood trauma.

The CEN is also more active than in healthy children, which means that children with trauma histories tend to ruminate and relive terrible experiences when triggered.

Dr Klabunde hopes this study will be a springboard to find out more about how trauma affects developing minds.

She said: "Our brain findings indicate that childhood trauma treatments appear to be missing an important piece of the puzzle.

"In addition to preventing avoidance of scary situations and addressing one's thoughts, trauma therapies in children should also address how trauma's impacts on one's body, sense of self, emotional/empathetic processing, and relationships.

"This is important to do so since untreated symptoms will likely contribute to other health and mental health problems throughout the lifespan."

Read more at Science Daily

New species of Jurassic pterosaur discovered on the Isle of Skye

A new species of pterosaur from specimens found on the Isle of Skye, Scotland, has been announced by scientists from the Natural History Museum, University of Bristol, University of Leicester, and University of Liverpool.

The new pterosaur is part of the Darwinoptera clade of pterosaurs.

Its discovery shows that the clade was considerably more diverse than previously thought, and persisted for more than 25 million years, from the late Early Jurassic to the latest Jurassic.

During this period species within the clade spread worldwide.

The discovery underpins a new and more complex model for the early evolution of pterosaurs.

The rarity of Middle Jurassic pterosaur fossils and their incompleteness has previously hampered attempts to understand early pterosaur evolution.

This discovery shows that all principal Jurassic pterosaur clades evolved well before the end of the Early Jurassic, earlier than previously realised.

The discovery also shows that pterosaurs persisted into the latest Jurassic, alongside avialans, the dinosaurs which eventually evolved into modern birds.

The remains consist of a partial skeleton of a single individual, including parts of the shoulders, wings, legs and backbone.

Many of the bones remain completely embedded in rock and can only be studied using CT-scanning.

Professor Paul Barrett, Merit Researcher at the Natural History Museum and senior author on the paper, said: "Ceoptera helps to narrow down the timing of several major events in the evolution of flying reptiles. Its appearance in the Middle Jurassic of the UK was a complete surprise, as most of its close relatives are from China. It shows that the advanced group of flying reptiles to which it belongs appeared earlier than we thought and quickly gained an almost worldwide distribution."

Prof. Barrett and his colleagues described the new species, naming it Ceoptera evansae: Ceoptera from the Scottish gaelic word Cheò, meaning mist (a reference to the common gaelic name for the Isle of Skye Eilean a' Cheò, or Isle of Mist), and the Latin -ptera, meaning wing.

Evansae honours Professor Susan E. Evans, for her years of anatomical and palaeontological research, in particular on the Isle of Skye.

Read more at Science Daily

Astronomers spot 18 black holes gobbling up nearby stars

Star-shredding black holes are everywhere in the sky if you just know how to look for them. That's one message from a new study by MIT scientists, appearing today in the Astrophysical Journal.

The study's authors are reporting the discovery of 18 new tidal disruption events (TDEs) -- extreme instances when a nearby star is tidally drawn into a black hole and ripped to shreds. As the black hole feasts, it gives off an enormous burst of energy across the electromagnetic spectrum.

Astronomers have detected previous tidal disruption events by looking for characteristic bursts in the optical and X-ray bands. To date, these searches have revealed about a dozen star-shredding events in the nearby universe. The MIT team's new TDEs more than double the catalog of known TDEs in the universe.

The researchers spotted these previously "hidden" events by looking in an unconventional band: infrared. In addition to giving off optical and X-ray bursts, TDEs can generate infrared radiation, particularly in "dusty" galaxies, where a central black hole is enshrouded with galactic debris. The dust in these galaxies normally absorbs and obscures optical and X-ray light, and any sign of TDEs in these bands. In the process, the dust also heats up, producing infrared radiation that is detectable. The team found that infrared emissions, therefore, can serve as a sign of tidal disruption events.

By looking in the infrared band, the MIT team picked out many more TDEs, in galaxies where such events were previously hidden. The 18 new events occurred in different types of galaxies, scattered across the sky.

"The majority of these sources don't show up in optical bands," says lead author Megan Masterson, a graduate student in MIT's Kavli Institute for Astrophysics and Space Research. "If you want to understand TDEs as a whole and use them to probe supermassive black hole demographics, you need to look in the infrared band."

Other MIT authors include Kishalay De, Christos Panagiotou, Anna-Christina Eilers, Danielle Frostig, and Robert Simcoe, and MIT assistant professor of physics Erin Kara, along with collaborators from multiple institutions including the Max Planck Institute for Extraterrestrial Physics in Germany.

Heat spike

The team recently detected the closest TDE yet, by searching through infrared observations. The discovery opened a new, infrared-based route by which astronomers can search for actively feeding black holes.

That first detection spurred the group to comb for more TDEs. For their new study, the researchers searched through archival observations taken by NEOWISE -- the renewed version of NASA's Wide-field Infrared Survey Explorer. This satellite telescope launched in 2009 and after a brief hiatus has continued to scan the entire sky for infrared "transients," or brief bursts.

The team looked through the mission's archived observations using an algorithm developed by co-author Kishalay De. This algorithm picks out patterns in infrared emissions that are likely signs of a transient burst of infrared radiation. The team then cross-referenced the flagged transients with a catalog of all known nearby galaxies within 200 megaparsecs, or 600 million light years. They found that infrared transients could be traced to about 1,000 galaxies.

They then zoomed in on the signal of each galaxy's infrared burst to determine whether the signal arose from a source other than a TDE, such as an active galactic nucleus or a supernova. After ruling out these possibilities, the team then analyzed the remaining signals, looking for an infrared pattern that is characteristic of a TDE -- namely, a sharp spike followed by a gradual dip, reflecting a process by which a black hole, in ripping apart a star, suddenly heats up the surrounding dust to about 1,000 kelvins before gradually cooling down.

This analysis revealed 18 "clean" signals of tidal disruption events. The researchers took a survey of the galaxies in which each TDE was found, and saw that they occurred in a range of systems, including dusty galaxies, across the entire sky.

"If you looked up in the sky and saw a bunch of galaxies, the TDEs would occur representatively in all of them," Masteron says. "It's not that they're only occurring in one type of galaxy, as people thought based only on optical and X-ray searches."

"It is now possible to peer through the dust and complete the census of nearby TDEs," says Edo Berger, professor of astronomy at Harvard University, who was not involved with the study. "A particularly exciting aspect of this work is the potential of follow-up studies with large infrared surveys, and I'm excited to see what discoveries they will yield."

A dusty solution

The team's discoveries help to resolve some major questions in the study of tidal disruption events. For instance, prior to this work, astronomers had mostly seen TDEs in one type of galaxy -- a "post-starburst" system that had previously been a star-forming factory, but has since settled. This galaxy type is rare, and astronomers were puzzled as to why TDEs seemed to be popping up only in these rarer systems. It so happens that these systems are also relatively devoid of dust, making a TDE's optical or X-ray emissions naturally easier to detect.

Now, by looking in the infrared band, astronomers are able to see TDEs in many more galaxies. The team's new results show that black holes can devour stars in a range of galaxies, not only post-starburst systems.

The findings also resolve a "missing energy" problem. Physicists have theoretically predicted that TDEs should radiate more energy than what has been actually observed. But the MIT team now say that dust may explain the discrepancy. They found that if a TDE occurs in a dusty galaxy, the dust itself could absorb not only optical and X-ray emissions but also extreme ultraviolet radiation, in an amount equivalent to the presumed "missing energy."

The 18 new detections also are helping astronomers estimate the rate at which TDEs occur in a given galaxy. When they figure the new TDEs in with previous detections, they estimate a galaxy experiences a tidal disruption event once every 50,000 years. This rate comes closer to physicists' theoretical predictions. With more infrared observations, the team hopes to resolve the rate of TDEs, and the properties of the black holes that power them.

"People were coming up with very exotic solutions to these puzzles, and now we've come to the point where we can resolve all of them," Kara says. "This gives us confidence that we don't need all this exotic physics to explain what we're seeing. And we have a better handle on the mechanics behind how a star gets ripped apart and gobbled up by a black hole. We're understanding these systems better."

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Increased temperature difference between day and night can affect all life on earth

Researchers from Chalmers University of Technology, in Sweden, have discovered a change in what scientists already knew about global warming dynamics. It had been widely accepted since the 1950s that global temperature rises were not consistent throughout the day and night, with greater nighttime warming being observed. However, the recent study reveals a shift in dynamics: with greater daytime warming taking place since the 1990s. This shift means that the temperature difference between day and night is widening, potentially affecting all life on Earth.

The rise in the global average surface temperature is one of the key characteristics of human-induced climate change.

However, the temperature increase is not uniform throughout the day and night, and nighttime temperatures have increased at a faster pace than daytime temperatures in the latter half of the twentieth century.

This warming pattern, with variations between day and night is termed "asymmetric warming" and could be due to both human activities and naturally occurring phenomena.

In a new study, published in Nature Communications, an international team of researchers reinvestigated the asymmetric warming phenomenon and found that the pattern has reversed.

Between 1961 and 2020, global daytime warming has accelerated, while the warming rate of nighttime temperature is relatively constant.

This reversed trend in asymmetric warming has led to an increasing temperature difference between day and night.

"We initially aimed to confirm the previously observed phenomenon of nighttime warming surpassing daytime warming. To our surprise, not only had the asymmetric warming trend ceased, but our analyses, based on state-of-the-art observation-based datasets, indicate a complete reversal of this original warming pattern over the past three decades," says Ziqian Zhong, post-doctoral researcher at Chalmers.

Global brightening a potential cause

"A likely explanation to this change is a phenomenon called "global brightening," which has been observed since the late 1980s. It is a result of less cloud cover, which causes more sunlight to reach the Earth's surface, leading to higher daytime temperatures and, as a result, a broader difference between daytime and nighttime temperatures over the recent decades," says Ziqian Zhong.

There is currently significant uncertainty regarding the reasons behind the changes in cloud cover.

The "global brightening" may be attributed to a complex interplay between cloud-free and cloudy atmospheres, as well as the effect of small particles in the atmosphere, known as aerosols.

These aerosols can be derived from natural processes like sea spray and wildfires, but also from human activities like fossil fuel burning, and they can have a profound effect on many aspects of the environment.

Apart from the effects from global brightening, the researchers suggest another reason for the reversed asymmetric warming.

The increase in regional drought events and heatwaves suggests a potential weakening of the cooling effect due to evaporation at the Earth's surface, which would typically result in a faster increase in daytime temperatures.

The researchers found that the majority of land, 81 per cent of the total area, experienced larger nighttime warming from 1961 to 1990.

However, in the subsequent period from 1991 to 2020, a shift occurred, with 70 per cent of the observed land areas experiencing larger daytime warming instead.

Affecting all life on Earth

The larger temperature difference between day and night could potentially affect crop yields, plant growth, animal well-being and human health.

For example, an increased temperature difference between daytime and nighttime is recognised as one of the environmental stressors that could lead to elevated heart rate and blood pressure, consequently increasing cardiac workload and the mortality and morbidity of cardiovascular and respiratory diseases.

"This indicates the need to adjust strategies in different areas affected by temperature variations between day and night, such as agriculture, public health, and forestry management, to address the challenges posed by this climate change," says Ziqian Zhong.

Certain tree species in humid areas might enhance their carbon sequestration capacity due to the increased temperature difference between daytime and nighttime.

However, the increased temperature difference between daytime and nighttime might prove disadvantageous for trees in dry regions, as higher daytime temperatures may increase evaporation, leading to deficiency of soil water and unfavorable conditions for tree growth.

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Ambitious roadmap for circular carbon plastics economy

Researchers from the Oxford Martin Programme on the Future of Plastics, University of Oxford, have outlined ambitious targets to help deliver a sustainable and net zero plastic economy. In a paper published in Nature, the authors argue for a rethinking of the technical, economic, and policy paradigms that have entrenched the status-quo, one of rising carbon emissions and uncontrolled pollution.

Currently the global plastics system results in over 1 gigatonnes per annum (Gt/annum) of carbon dioxide equivalent emissions which is the same as the total combined emissions of Europe's three largest economies (UK, Germany and France). If left unchecked, these emissions could rise to 4-5 Gt/annum with other sources of pollution also causing concern.

Another problem is the lack of effective recycling -- in 2019, only 9% of the world's plastic waste was turned into new products through mechanical recycling.

The majority ended up in landfills or was incinerated, and a significant proportion was mismanaged, ending up polluting terrestrial and marine ecosystems.

The authors analyse the current and future global plastics system, proposing technical, legal, and economic interventions from now until 2050 to allow it to transition to net zero emissions and to reduce other negative environmental impacts.

The study includes a future scenario centred on four targets:

• Reducing future plastics demand by one half, substituting and eliminating over-use of plastic materials and products.
• Changing the way plastics are manufactured to replace fossil fuels as the hydrocarbon source to use only renewably raw materials, including waste biomass and carbon dioxide.
• For plastics which are recoverable, maximising recycling very significantly, targeting 95% recycling of those materials which are retrievable from wastes.
• Integrating plastic manufacturing and recycling with renewable power and minimising all other negative environmental impacts, including of additives.

The authors emphasise the need for concerted action across all four target areas to ensure the global plastics systems curbs its climate impacts and meets UN Sustainable Development Goals.

Charlotte Williams, Professor of Chemistry at the University of Oxford's Department of Chemistry and lead author said:

'We need plastics and polymers, including for future low emission technologies like electric vehicles, wind turbines, and for many essential everyday materials.

Our current global plastics system is completely unsustainable, and we need to be implementing these series of very bold measures at scale, and fast.

This is a solvable problem but it needs coherent and combined action, particularly from chemical manufacturers.'

To successfully transition the plastics system, the authors set out principles to ensure 'smart materials design' and differentiate between plastics which are recoverable and irretrievable after use, noting that there is not a one size fits all solution.

Rather, the authors propose careful use of the design principles to help select the optimum production methods and appropriate use of resources, deliver the required performances, ensure waste management, and minimise broader environmental impacts.

A timeline of technical-economic-policy and legal interventions helps readers focus on the actions needed to reach net zero emissions by 2050.

'The time for action has arrived, we cannot afford to wait any longer,' study co-author Fernando Vidal, Postdoctoral Researcher in Chemistry at POLYMAT in Spain and former Oxford Martin School Fellow on the Future of Plastics concluded.

'We must change our concepts around the way we make, use, and dispose of plastics, otherwise we risk perpetuating this problem.

The upcoming UN Global Plastic Treaty is the opportunity to make a lasting change in the right direction.'

Study co-author Cameron Hepburn, Battcock Professor of Environmental Economics at the Oxford's Smith School of Enterprise and the Environment, said: 'The problem is that plastics, while contributing hugely to global pollution and greenhouse gas emissions, are extraordinarily useful.

Our research finds that creating a circular economy for plastics in order to reduce their negative impacts is possible, but only if we can reduce future demand by half, switch to renewable plastics that aren't made from fossil fuels, recycle 95% of what's left, and minimise environmental impacts at every step of the process.

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Scammed! Animals 'led by the nose' to leave plants alone

University of Sydney researchers have shown it is possible to shield plants from the hungry maws of herbivorous mammals by fooling them with the smell of a variety they typically avoid.

Findings from the study published in Nature Ecology & Evolution show tree seedlings planted next to the decoy smell solution were 20 times less likely to be eaten by animals.

"This is equivalent to the seedlings being surrounded by actual plants that are unpalatable to the herbivore. In most cases it does trick the animals into leaving the plants alone," said PhD student Patrick Finnerty, the study's lead author from the School of Life and Environmental Sciences Behavioural Ecology and Conservation Lab.

"Herbivores cause significant damage to valuable plants in ecological and economically sensitive areas worldwide, but killing the animals to protect the plants can be unethical," he said.

"So, we created artificial odours that mimicked the smell of plant species they naturally avoid, and this gently nudged problematic herbivores away from areas we didn't want them to be.

"Given that many herbivores use plant odour as their primary sense to forage, this method provides a new approach that could be used to help protect valued plants globally, either in conservation work or protecting agricultural crops."

The experiment, conducted in Ku-ring-gai Chase National Park in Sydney, used the swamp wallaby as model herbivore.

The researchers selected an unpalatable shrub in the citrus family, Boronia pinnata, and a palatable canopy species, Eucalyptus punctata, to test the concept.

The study compared using B. pinnata solution and the real plant and found both were equally successful at protecting eucalyptseedlings from being eaten by wallabies.

As part of his doctoral research, Mr Finnerty has also tested the method successfully with African elephants, but that fieldwork does not form part of this research paper.

Previous attempts to use repellent substances, such as chilli oil or motor oil, to control animal consumption of plants have inherent limitations, Mr Finnerty said.

"Animals tend to habituate to these unnatural cues and so deterrent effects are only temporary," he said.

"By contrast, by mimicking the smell of plants herbivore naturally encounter, and avoid in day-to-day foraging, our approach works with the natural motivators of these animals, with herbivores less likely to habituate to these smells."

Researchers took this idea and used solutions that produce these undesired aromas.

"As a management tool to protect palatable plants, our technique offers many advantages over real plants as a repellent," Mr Finnerty said.

"Our approach should be transferable to any mammalian, or potentially invertebrate, herbivore that relies primarily on plant odour information to forage and could protect valued plants globally, such as threatened species."

Current solutions to herbivore-related problems often involve costly and environmentally impactful measures such as lethal control or fencing.

The new research introduces an alternative low-cost, humane strategy based on understanding herbivores' foraging cues, motivations and decisions.

"Plant browsing damage caused by mammalian herbivore populations like deer, elephants and wallabies is a growing global concern," said senior study author Professor Clare McArthur.

"This damage is one of the greatest limiting factors in areas of post-fire recovery and revegetation, destroying more than half the seedlings in these areas. It also threatens endangered plants and causes billions of dollars of damage in forestry and agriculture globally.

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